February 1, 2014 | Vol 70, No 2

The Great China Geoduck Ban Mystery

By Michael A. Moore

US shellfish farmers and harvesters, scientists, and government officials are mystified by China\'s ban on the importation of bivalves originating from the US West Coast – just in time to affect the geoduck harvest intended to supply the peak Chinese New Year market in China, when prices skyrocket. Photo courtesy of Taylor Shellfish.

China's ban on the importation of bivalves originating from the US West Coast could not have come at a worse time for the commercial producers and harvesters of oysters, clams and geoducks – especially geoducks.

Notice of the Chinese prohibition was received by NOAA's Seafood Inspection Office in mid-December – just in time to affect the geoduck harvest intended to supply the peak Chinese New Year market in China, when prices skyrocket.

NOAA estimates it will take at least two or three months to overcome the prohibition on US origin bivalves. By that time, China's New Year celebrations will be memories.

Meanwhile, back in the USA, shellfish farmers and harvesters, scientists, and government officials are mystified by the ban and the little bit of information they have been given as justification for the action.

"While the shipments of shellfish that resulted in this ban by China were wild harvest geoduck, the ban applies to "all double-shelled aquatic animals" imported into China from US portion of "area 67," which includes Alaska to mid-California," said Margaret P. Barrette, Executive Director of the Pacific Coast Shellfish Growers Association.

"I am not aware of significant shipments of US west coast oysters being sent to China at this time, so the immediate impact of this ban falls primarily on the export of geoduck. Earlier reports indicated that geoduck from Washington and Alaska tested high for PSP and arsenic."

It turned out that Washington geoducks were not contaminated with PSP.

"We received confirmation this morning that the shipment related to our state was an arsenic concern; the shipment related to Alaska was a PSP concern," stated Jerrod Davis of the Washington Department of Health in a press release.

"The Washington product originated from Poverty Bay in Redondo," said Margaret Barrette. "The Alaska product originated from the Ketchikan region. While we are waiting confirmation, NOAA believes that the Chinese reports indicate that the Washington product tested above China's standard for arsenic and the Alaska product tested above the US standard for PSP.

"We are still trying to confirm the testing protocol used by the Chinese officials, how notification was handled, and why the entire West Coast was closed as opposed to targeting just the area from where the implicated product was harvested. One key request that we have made to the federal agencies is that, if the issue is limited to one specific growing area in each state, that the other unaffected growing areas be immediately reopened for shipment."

"The China tests results on geoducks from the Poverty Bay area said the results for inorganic arsenic were above their standard of 0.5 parts per million (500 parts per billion)," according to a Department of Health press release.

"We don't know what testing method China used, but we are trying to get that information. Until we know how the tests were performed, we can't assess China's results. To be safe, and until we know more, the harvest area that produced the geoducks China tested has been closed by the Department of Natural Resources."

Those levels reported by China are about 10 times higher than the average levels the Department of Health has seen in the Puget Sound area, where the average range is 10-40 parts per billion.

The Department of Health released the results of their own toxicology studies on January 7, 2014. The department did targeted testing in Poverty Bay in 2007 because of

concerns about possible contamination from a sewage treatment outfall in the area. In this 2007 study, they tested five geoducks from each of 24 sites in the bay, and did not find arsenic levels that were a health concern.

The announcement further stated that geoduck harvesting in Poverty Bay is closed until more information is available about the Chinese test results.

"These test results confirm our expectation that it's safe to eat geoducks harvested from the Poverty Bay area of Puget Sound," said Secretary of Health John Wiesman. "We've given the test results to our state partners and to the federal partners that are working directly with China."

These findings have been conveyed to authorities in China by the US National Oceanic and Atmospheric Administration (NOAA) Seafood Inspection Program.

The Department of Health announcement does nothing to clarify the anomalous test results from China – the mystery remains.

"There are two questions I would like answered by the Chinese," said Rosalind Schoof, a PhD toxicologist working with the Pacific Coast Shellfish Growers Association to assist on the arsenic issue.

"One, did they test the whole animal? The Chinese standard specifically applies to the edible portions of the animal," she said. If they tested the skin, there is a possibility that the results showed higher levels of inorganic arsenic than the edible portions of the geoduck.

Another factor that could affect the results would be if they tested for whole arsenic and extrapolated the amount of inorganic arsenic present.

"The value they reported is much higher than what we've seen in prior testing of Puget Sound geoducks. It's unclear as to why there should that discrepancy," Schoof said, mentioning a 2007 study done by the Suquamish Tribe's Fisheries Department and the Washington Department of Health.

"Tissues from 60 geoducks collected from the Richmond Beach tract were segregated into three parts: viscera, siphon/mantle, and the outer skin of the siphon," reported the study.

"Viscera and siphon/mantle tissues from each geoduck were separately analyzed for total arsenic, cadmium, chromium, lead, and mercury. Composites of viscera and siphon/mantle tissues were analyzed for inorganic arsenic. A subset of tissues from the outer skin of siphons was also analyzed. In general, trace metal concentrations were highest in the outer skin, and lowest in the siphon/mantle. The results from this study have helped to explain inconsistent results among past studies and suggest some considerations in future studies or health assessments of geoduck tissues."

"My second question is if the tests are of wet or dry samples," said Schoof. "It's an important distinction. Shellfish are between 85 to 90% water. Some labs dry fish out and the results are approximately ten times higher than the same weight wet."

The mystery deepens further with the fact that China has not placed any restrictions on bivalves and geoducks from British Columbia – which raises questions, considering that Area 67, the harvest area restricted by the Chinese, goes from California to Siberia.

"The Canadian Food Inspection Agency is still issuing certifications for geoduck exports to China," said a NOAA official off the record.

One independent observer has speculated that the geoduck ban and its timing could be due to factors more political than scientific.

"It is possible that it could be retaliation for something," said Tabitha Mallory, a postdoctoral research fellow at the Princeton-Harvard China and the World Program, in an interview with Ashley Ahearn of EarthFix.

"That has happened in the past. There's an example regarding Norway a few years ago," said Mallory. "China has banned salmon imports from Norway and that coincided with the Nobel Peace Prize being awarded to the political activist Liu Xiaobo in 2010.

"So, the Norwegians have said that the Chinese have found problems with pathogenic microorganisms in the fish and high levels of veterinary drugs, but the timing is really interesting, that the ban was put in place right around the same time as the prize being awarded.

"With regard to the geoduck ban, it took place right around the time of the WTO ministerial meeting in Indonesia. And I'm not sure if there's any connection there, but there might be."

Rumors are also floating around that the ban and its timing may have more to do with disgruntled distributors in British Columbia who previously marketed Washington and Alaska bivalves to Hong Kong and China. That situation changed a few years back when Washington shellfish harvesters started their own direct marketing efforts to Hong Kong and Mainland China.

Whatever the reason behind the great geoduck ban mystery, Bill Dewey of Taylor Shellfish would like to get the situation resolved as quickly as possible.

"I don't blame the Chinese," said Taylor. "We are still exporting to Hong Kong, but the real market, especially for the New Year season, is Mainland China."